1. Field of the Invention
The present invention relates to a plasma display panel (PDP), and in particular, to a PDP having bus electrodes with an improved shape, thereby enhancing the PDP's contrast and discharge characteristics.
2. Discussion of the Background
Generally, a PDP displays images using plasma discharge. Applying voltages to electrodes formed on substrates of the PDP generates a plasma discharge between the electrodes, which generates ultraviolet rays. The ultraviolet rays excite phosphor layers to display desired images.
PDPs may be classified into an alternating current (AC) type, a direct current (DC) type, and a hybrid type.
FIG. 1 is an exploded perspective view of an AC PDP 100. As shown in FIG. 1, the PDP 100 includes a bottom substrate 104, address electrodes 102 formed on the bottom substrate 104, a dielectric layer 106 covering the address electrodes 102, a plurality of barrier ribs 105 formed on the dielectric layer 106, and phosphor layers 101 formed on the dielectric layer 106 and sides of the barrier ribs 105.
Display electrodes 112, comprising transparent electrodes 107 and bus electrodes 108, are formed orthogonally to the address electrodes 102 on a top substrate 110. A dielectric layer 109 and a protective layer 103 cover the display electrodes 112.
With the above-structured PDP 100, applying driving voltages to the address and bus electrodes 102 and 108 generates an addressing discharge between them, thereby forming wall charges within the selected discharge cells. Alternating current signals may then be alternately applied to the display electrodes 112 of the selected discharge cells, thereby generating the sustain discharge.
The AC PDP's transparent electrodes 107 are typically formed with indium oxide (In2O3), and they are often referred to as indium tin oxide (ITO) electrodes. The ITO electrodes are transparent, and they are evenly formed on the large-sized panel with excellent affinity with the neighboring materials. However, since the ITO electrodes have relatively low conductivity, Ag or Cr—Cu—Cr bus electrodes may be formed along an edge of the ITO electrodes to achieve the required electrical conductivity. The bus electrodes normally extend to the periphery of the panel, where they may be coupled to driving circuits. The address electrodes are often formed with a highly-conductive Ag paste material.
FIG. 2 is a partial sectional view of the top substrate 110 of the PDP 100. As shown in FIG. 2, the bus electrodes 108 may be composed of white electrode portions 1081(W) and black electrode portions 1082(B).
As shown in FIG. 2, conventionally formed bus electrodes 108 may have curl shapes at both edges. Vapors may form within the dielectric layer (109 of FIG. 1) due to these edge curls when the dielectric layer 109 is formed covering the bus electrode 108, thereby causing the inter-voltages of bus electrodes 108 to drop and mis-discharge to occur in the discharge cells corresponding to such electrodes. Therefore, an improved electrode structure is desired.